Gallium hydride, addition

The simple, salt elimination reaction of Equation (8.1) has been employed for amides of all the group 13 metals. In addition, it is currently the only well-established route to M(I) metal amides where M = Ga or Tl. The alkane elimination route of eqn. (8.2) is generally employed only for M = Al or Ga. This synthetic approach is also used for the metal imides (RMNR )n where a primary amine H2NR is the reactant. The use of metal hydrides, of which Equation (8.3) is but one example, is limited mainly to aluminium and, to a lesser extent, gallium because of the decreased stability of the heavier metal hydrides. 

The trimethylamine adduct of aluminum hydride (alane) has been of recent interest as a precursor for the chemical vapor deposition (CVD) of aluminum metal1 and aluminum gallium arsenide thin films.2 Because of the absence of aluminum-carbon covalent bonds in the precursor, carbon incorporation in the resulting films can be suppressed significantly. In addition, the deposition temperature can be lowered. 

The formation of gallium(lll) hydrides in ZSM5 through oxidative addition of hydrogen to Ga(l) was reported by Kazansky et al. (2004), e.g. 

In addition to the reactant gases listed in Table 5, hydride dopants (e g., arsine, phosphine, diborane) may be introduced to control the type of conductivity and resistivity of the film layer. For silicon films, the dopant gases are introduced in small amoimts (e.g., ppb levels) while for III-V films, the concentrations used are considerably higher (e.g., percentage concentrations). For molecular beam epitaxy (MBE), solid gallium is used for P-type doping and antimony for N-type doping. 

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